I have to be missing something simple...and yes, I am a Scratch newbie.
I have Scratch Lab running on macbookpro retina with an Aja t-tap. I have the scratch logo on the 2nd monitor, via the t-tap and sdi...but when I go to matrix and play I get nothing. Just the same logo on the screen. I have tried a bunch of different setups for sdi, and still no luck. I do see a little notification about VCR not enabled or something like that...but I don think that is related.